The present invention relates to an automobile antenna whose antenna body, comprising an antenna element, is attached to the vehicle body.
This type of automobile antenna is generally mounted on the roof panel 20 of the automobile as shown in FIG. 10.
The antenna body 1 of this automobile antenna comprises an antenna cover 1a and an element portion 8 attached to the antenna cover 1a; a base portion, not shown, is fixed to the lower end of the antenna cover 1a. As shown in FIG. 11a, a cylindrical projecting portion 13 is formed on the lower surface of this base portion so as to project therefrom. The antenna body 1 is fixed to the roof panel 20 by screwing a fixing nut 2 onto this cylindrical projecting portion 13. In this case, the base portion of the cylindrical projecting portion 13 is a rectangular projecting portion. A rectangular antenna mounting hole 21 is formed in the roof panel 20, as shown in FIG. 11b, such that the rectangular projecting portion can be inserted therein.
When such an antenna body 1 is attached to the roof panel 20, the rectangular projecting portion formed on the base portion is inserted in a rectangular antenna mounting hole 21 formed in the roof panel 20, and a worker located outside the vehicle body holds the antenna body 1 so that the antenna body 1 will not come out of the antenna mounting hole 21. In this state, another worker located within the vehicle body screws the fixing nut 2 onto the cylindrical projecting portion 13 projecting into the vehicle body and tightens the fixing nut 2, whereby the antenna body 1 is affixed to the roof panel 20 as shown in FIG. 11a. 
The element portion 8 may be constructed such that it can be removed from the antenna cover 1a so that the element portion 8 is not damaged from the impact of the rotating brushes or the like of a car washing machine when the vehicle is washed, or from contact with the ceiling of a garage when the vehicle is parked.
In this way, two workers, inside and outside the vehicle body, are needed to mount a conventional automobile antenna, and thus such conventional automobile has a problem that the large number of workers needed for the mounting operation.
It is an object of the present invention to provide an automobile antenna that can be mounted on the vehicle body by one worker.
In order to achieve the abovementioned object, the automobile antenna relating to the present invention comprises a base portion for fixing an antenna body having at least an antenna element to a vehicle body;
wherein a rectangular projecting portion to be inserted in a rectangular mounting hole formed in the vehicle body and a cylindrical projecting portion, extending from the rectangular projecting portion and onto which a fixing nut disposed inside the vehicle body is screwed, are formed so as to project from the lower surface of said base portion;
a fixing plate, whereon are formed spring portions for engaging with the edge of the mounting hole and temporarily fixing said antenna body to said vehicle body when said rectangular projecting portion is inserted in said mounting hole, is fixed to said base portion;
the fixing plate is formed to have a U-shaped cross section; said spring portions are formed on the opposite side plates thereof so as to incline outwards; and the side plates are inserted through holes formed in said base portion and project from the rear surface of said base portion.
Also, in the abovementioned automobile antenna relating to the present invention, a part of said side surface of said cylindrical projecting portion may be notched along the side plates of said fixing plate, so that the surfaces of the side plates of the fixing plate do not project outwards beyond the side surface of said cylindrical projecting portion.
Furthermore, in the abovementioned automobile antenna relating to the present invention, said fixing plate may be formed integrally as a single piece with a board bracket for holding a printed wiring board fixed to the surface of said base portion.
In addition, in the abovementioned automobile antenna relating to the present invention, said fixing plate may be held between and fixed to said base portion and said board bracket, by fixing the board bracket for supporting the printed wiring board to said base portion.
According to such an invention, the spring portions formed on the fixing plate can engage with the mounting hole and fix the antenna body to the vehicle body, when the rectangular projecting portion formed on the base portion is inserted in the mounting hole formed in the vehicle body. Consequently, the antenna body can be fixed on the vehicle body in this state by a worker entering the vehicle and screwing and tightening the fixing nut onto the threaded portion.
For this reason, the automobile antenna can be fixed to the vehicle body by just one worker.
Also, the fixing plate, which is formed to have a U-shaped cross section, is fixed by inserting the opposite side plates whereon are formed spring portions so as to incline outwards into the hole portion formed in the base portion; as a result, the fixing plate can be fixed with sufficient strength to the base portion. In this case, the board bracket formed as a single piece with the fixing plate is attached to the base portion, the fixing plate is held by the base portion and board bracket, and the board bracket is attached to the base portion thereby.
Furthermore, part of the side surface of the cylindrical projecting portion along the side plates of the fixing plate is cut away so that the surfaces of the side plates of the fixing plate do not project outside of the side surface of the cylindrical projecting portion. As a result, when the cylindrical projecting portion formed on the base portion is inserted in the mounting hole formed in the vehicle body, the cylindrical projecting portion can be smoothly inserted in the mounting hole, without the fixing plate located on the side surface of the cylindrical projecting portion striking the edge portion of the mounting hole.